1. Technical Field
The present disclosure relates to formable surgical fasteners and, more particularly, to surgical staples for use in surgical staplers having an end effector including a cartridge assembly for deploying the surgical staples and an anvil for forming the surgical staples. The present disclosure also relates to cartridge assemblies configured to carry and deploy the surgical staples and anvil assemblies for forming the surgical staples.
2. Background of Related Art
Many varieties of surgical fastening apparatus are known in the art, some of which are specifically adapted for use in various surgical procedures including, but not limited to, end-to-end anastomosis, open gastrointestinal anastomosis, endoscopic gastrointestinal anastomosis, and transverse anastomosis. Suitable examples of apparatus which may be used during the course of these procedures can be seen in U.S. Pat. Nos. 5,915,616; 6,202,914; 5,865,361; and 5,964,394, each of which is hereby incorporated by reference herein in its entirety.
In general, a surgical fastening apparatus will include an anvil that is approximated relative to a fastener cartridge during use. The anvil includes depressions that are aligned with, and/or are in registration with slots defined in the cartridge, through which the fasteners will emerge, to effectuate formation. The fastener cartridge typically has one or more rows of fasteners disposed laterally or radially of a longitudinal slot that is configured to accommodate a knife, or other such cutting element, such that tissue can be simultaneously cut and joined together. Depending upon the particular surgical fastening apparatus, the rows of fasteners may be arranged in a linear or non-linear, e.g. circular, semi-circular, or otherwise arcuate configuration.
Various types of surgical fasteners are well known in the art, including but not limited to unitary fasteners and two-part fasteners. Unitary fasteners generally include a pair of legs adapted to penetrate tissue and are connected by a backspan from which they extend. The staples are formed into a closed configuration, such as a “B” shaped configuration. Typically, the two-part fastener includes legs that are barbed and connected by a backspan. The legs are engaged and locked into a separate retainer piece that is usually located in the anvil. In use, the two-part fastener is pressed into the tissue so that the barbs penetrate the tissue and emerge from the other side where they are then locked into the retainer piece. The retainer piece prevents the two-part fastener from dislodging from the tissue. The two-part fasteners are not intended to be unlocked or removable. The fasteners are generally made of a bioabsorbable material.
During each of the aforementioned surgical procedures, the tissue is initially gripped or clamped between the anvil and cartridge such that individual fasteners can be ejected from the cartridge, through the slots, and forced through the clamped tissue. Thereafter, the fasteners are formed by driving them into the depressions formed in the anvil.
Laparoscopic Endo GIA™ reloads or cartridge assemblies are usually 12 mm in diameter. Some cartridge assemblies used to staple relatively thick tissue are 15 mm in diameter. “B” staples use linear pushers to keep the staples constrained within a pocket of a cartridge assembly during their deployment. “B” staples are guided from all sides to ensure acceptable forming. Traditional staple-pusher-sled configurations, however, are too big to fit a 5 mm diameter stapler.
Accordingly, there is a growing need to make staplers having cartridge assemblies that are smaller than 12 mm in diameter, with 5 mm cartridge assemblies being the most desirable. There is also a growing need for surgical staples that occupy less space within a cartridge assembly prior to deployment. Pediatric, thoracic and hepato-biliary and pancreatic surgeons could benefit from such devices. Further, it would simplify port management if a cartridge assembly could fit into a 12 mm port. Smaller cartridge assemblies will also enable new multi-firing staplers, which may be capable of being reloaded inside of body cavities.
It would therefore be desirable to provide a staple configuration for a staple designed to penetrate tissue and contact an anvil pocket on the opposing side of tissue, which, in cooperation with conventional cartridge and anvil technology, minimizes staple size and therefore cartridge assembly size.